Internet-of-Things (IoT) refers to a technology of connecting all devices to the Internet by building a control unit (i.e., computer chip) and a communication unit in each of the devices.
IoT devices refer to common devices or things having a built-in IoT function. For example, general home appliances such as CCTVs, lights, alarms, refrigerators, air-conditioning devices can be IoT devices. In addition, various sensors that are commonly found in industrial sites, security devices, transformers, circuit breakers, energy storage devices, medical devices, factory automation devices, etc. also can be IoT devices.
Users can control IoT devices remotely from their IoT-based user terminals. User terminals and IoT devices are connected via various communication networks such as home networks, wireless communication networks, and short-range communication networks. Users are given authority to access and control IoT devices.
One of the key components for enabling users to remotely control various IoT devices from their user terminals is a controller for controlling an IoT device. Most frequently used controllers are a programmable logic controller (PLC) and an application-specific control board which is configured such that an electronic component such as a microcontroller unit (MCU) is mounted on a printed circuit board (PCB).
While an application-specific control board is a customized controller that is designed and manufactured according to the specifications required by an electric/electronic product in which the control board is to be built, a PLC is a general-purpose control board in which extra relays, DC inputs, contact inputs, and analog input terminals are included.
Conventional application-specific control boards for implementing an IoT service are designed and manufactured according to the types and the number of peripherals (for example, sensors, actuators, and valves) to be used in a specific IoT environment. Accordingly, a conventional application-specific control board has a problem in that the circuit thereof needs to be redesigned or replaced every time a new IoT device is added to the existing IoT environment or each existing IoT device is upgraded.
On the other hand, in the case of PLCs that are programmed using a ladder logic which is a programming language in the form of a graphical user interface (GUI), they are advantageous in that they can be relatively easily modified when there is a change in use of an existing device and their function can be easily extended.
As described above, conventionally, extension of functions and maintenance of control boards are burdensome and costly. Therefore, once an IoT environment is established, the IoT environment is continuously used as it is without addition of new IoT devices to the existing IoT device or modification to the existing IoT devices.